1. Field of the Invention
The present invention generally relates to igniters or heat sources and, more particularly to an igniter/heat source having a relatively low profile.
2. Prior Art
Various types of igniters and heat sources are well known. In most prior art devices, there is a non-combustible portion of the igniter which is used to contain the combustible portion. Several such prior art devices are disclosed in U.S. Pat. Nos. 2,953,443; 2,999,460; 3,961,579; 4,013,061; 4,216,721; 4,407,200; 4,269,120. U.S. Pat. No. 4,464,989 discloses a thermite igniter/heat source comprising a container holding an internal igniter load wherein the container consists essentially of consumable consolidated thermite having a low gas output upon combustion, whereby upon ignition, substantially all of the container and the load are consumed with low gas production.
U.S. Pat. No. 3,961,579 discloses a thermite destructive device for melting volumes through metal items. The device includes a fuse which is dispersed through a lid which covers a top opening. The device includes a bottom member having an opening and an easily burnable cover. The outer casing remains intact throughout the burn cycle.
U.S. Pat. No. 4,407,200 discloses a detonator which includes an opening which is closed off with "the usual cover disks". The detonator includes two different explosives. A lacquer coating is disposed over the "firing side" of the detonator, the other side being closed off with a cap. The explosives can be packed into a cap member.
U.S. Pat. No. 2,953,443 discloses a chemical heating device comprising dense autogenous combustible material and slow-burning combustible material. The dense material is formed into an apex pointing toward the initial burning point. The slower-burning combustible material surrounds an ignition wire at the ignition point. The ends of the device are capped off with top and bottom plugs.
U.S. Pat. No. 4,216,721 discloses a thermite penetration device formed in the shape of a cone. The bottom of the device has a hole which permits the egress of reaction products.
U.S. Pat. No. 4,013,061 discloses a thermite heating device comprising a hermetically sealed cartridge containing alumino-thermic materials. The materials are formed with a cone-shaped depression adjacent to the percussion primer cap and the depression is filled with ignition materials.
It is an objective of the present invention to provide a new low-energy externally ignitable thermite igniter/heat source e.g., for use in igniting larger charges such as propellant charges, or for use as a torch.
It is another objective of the present invention to provide a low-profile device which is externally ignitable that can focus the energy of a pyrotechnic reaction by means of a torch-like ejection of hot reaction products. Such ignition can be accomplished by virtually any heat source such as an electrical discharge through a hot wire, or another pyrotechnic reaction. This type of device is needed as a dependable, very compact heat source or ignition source for various purposes, such as for penetration of metallic or other solid objects and/or their destruction or obliteration.